Looking at the options, I've narrowed it down to three that I'm interested in.
1. Digital America, a new online journal. About submissions, they state "We are soliciting critical essays, film, artwork, design, and process pieces that question, analyze, and/or hack the tools of digital culture." Mine is basically an essay on the idea of the digital world and how that has evolved over time, so with some minor changes it would work great. It seems pretty easy to submit to, not super academic, but big enough that people could see my name. I haven't submitted here, but I might in the future.
2. Student Pulse is more academic, might be less likely to accept a paper that is so much about virtual worlds, but then I could emphasize the Renaissance aspect of it more. It accepts undergraduate work, so that's good, with "a particular focus on the social sciences, arts, and humanities." It requires more than 1500 words, though, so perhaps this would be better for Ahna...I haven't submitted to this one.
3. Re:Humanities is a symposium on digital media, so this seems like a good fit. This year, the focus is bleeding edge and cutting edge, basically the risks of trying to stay relevant. The idea of Second Life and the virtual world is all about this kind of risk and reward situation. One of the ideas they want to talk about is "Identity as shaped by excessive information or data deprivation." I've submitted to this symposium, we'll see how it goes.